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48
1 17M-0479 WEATHERING AND CORROSION TESTING IN THE AUTOMOTIVE INDUSTRY: AN OVERVIEW OF TODAY’S REQUIREMENTS Andy Francis, Q-Lab Corporation

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Page 1: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

1 17M-0479 1 17M-0479

WEATHERING AND CORROSION TESTING IN THE AUTOMOTIVE INDUSTRY AN OVERVIEW OF TODAYrsquoS REQUIREMENTS Andy Francis Q-Lab Corporation

2 17M-0479 SAE INTERNATIONAL 2 17M-0479

Weathering and Corrosion

Weathering

Changes in material properties resulting from exposure to the radiant energy present in sunlight in combination with heat (including temperature cycling) and water in its various states predominately as humidity dew and rain

(Atmospheric) Corrosion

Deterioration and destruction of a material and its vital properties due to electrochemical reactions on the surface of a metal in an atmospheric environment It occurs when the surface is wet by moisture formed due to rain fog and condensation

3 17M-0479 SAE INTERNATIONAL 3 17M-0479

Weathering and Corrosion Testing

Weathering Corrosion

Outdoor Accelerated Outdoor Accelerated

4 17M-0479 SAE INTERNATIONAL 4 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

5 17M-0479 SAE INTERNATIONAL 5 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

6 17M-0479 SAE INTERNATIONAL 6 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

7 17M-0479 SAE INTERNATIONAL 7 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 2: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

2 17M-0479 SAE INTERNATIONAL 2 17M-0479

Weathering and Corrosion

Weathering

Changes in material properties resulting from exposure to the radiant energy present in sunlight in combination with heat (including temperature cycling) and water in its various states predominately as humidity dew and rain

(Atmospheric) Corrosion

Deterioration and destruction of a material and its vital properties due to electrochemical reactions on the surface of a metal in an atmospheric environment It occurs when the surface is wet by moisture formed due to rain fog and condensation

3 17M-0479 SAE INTERNATIONAL 3 17M-0479

Weathering and Corrosion Testing

Weathering Corrosion

Outdoor Accelerated Outdoor Accelerated

4 17M-0479 SAE INTERNATIONAL 4 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

5 17M-0479 SAE INTERNATIONAL 5 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

6 17M-0479 SAE INTERNATIONAL 6 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

7 17M-0479 SAE INTERNATIONAL 7 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 3: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

3 17M-0479 SAE INTERNATIONAL 3 17M-0479

Weathering and Corrosion Testing

Weathering Corrosion

Outdoor Accelerated Outdoor Accelerated

4 17M-0479 SAE INTERNATIONAL 4 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

5 17M-0479 SAE INTERNATIONAL 5 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

6 17M-0479 SAE INTERNATIONAL 6 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

7 17M-0479 SAE INTERNATIONAL 7 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 4: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

4 17M-0479 SAE INTERNATIONAL 4 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

5 17M-0479 SAE INTERNATIONAL 5 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

6 17M-0479 SAE INTERNATIONAL 6 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

7 17M-0479 SAE INTERNATIONAL 7 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 5: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

5 17M-0479 SAE INTERNATIONAL 5 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

6 17M-0479 SAE INTERNATIONAL 6 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

7 17M-0479 SAE INTERNATIONAL 7 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 6: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

6 17M-0479 SAE INTERNATIONAL 6 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

7 17M-0479 SAE INTERNATIONAL 7 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 7: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

7 17M-0479 SAE INTERNATIONAL 7 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 8: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

8 17M-0479 SAE INTERNATIONAL 8 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 9: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

9 17M-0479 SAE INTERNATIONAL 9 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 10: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

10 17M-0479 SAE INTERNATIONAL 10 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 11: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

11 17M-0479 SAE INTERNATIONAL

Weathering Testing

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 12: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

12 17M-0479 SAE INTERNATIONAL 12 17M-0479

Historical Accelerated Weathering Test Standards

bull Several different tester architectures for light delivery ndash Xenon arc ndash Fluorescent UV ndash Others (carbon arc metal halide)

bull Xenon arc light sources reproduce full-spectrum sunlight

bull Hardware-based ldquo10218rdquo lightlight+spray standards were the first widely-used weathering standard tests ndash Almost 100 years old but still in use ndash Common examples ISO 4892-2 ASTM G155 Cycle 1 ISO 113 ndash OK for passfail but not realistic

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 13: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

13 17M-0479 SAE INTERNATIONAL 13 17M-0479

SAE J2527 Significant improvement hellip but still a ways to go

bull SAE J2527 (J1960) became the ldquostate of the artrdquo in 1980rsquos bull Research into primary stressors (light water heat) bull Replicated gloss loss seen in Florida exposures

bull This SAE weathering standard was well-researched and a leap forward but did not match real-world weathering factors

bull Light spectra bull Moisture delivery

bull As a result it did not adequately predict Florida outdoor field failures for very durable coatings

bull Chemical change (Photo-oxidation water-based effects) bull Physical change (Cracking Blistering Delaminating)

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 14: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

14 17M-0479 SAE INTERNATIONAL 14 17M-0479

Modern Weathering Test Standard Development

bull Outdoor weather data collected to understand real-world weather conditions sunlight heat and water

bull Outdoor weathering test dataset collected to provide basis for correlation

bull Accelerated test cycles developed to match those real-world conditions and degradation mechanisms

bull Variety of materials and failure modes evaluated with accelerated testing to verify validity of test

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 15: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

15 17M-0479 SAE INTERNATIONAL 15 17M-0479

Sunlight

Heat

Water

Collect outdoor weather data

Goal Obtain suitable body of field data to develop realistic Accelerated laboratory tests

Approach collect outdoor weather data to better understanding the forces of natural weathering

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 16: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

16 17M-0479 SAE INTERNATIONAL 16 17M-0479

bull Include both common field failures amp control materials

bull Use multiple replicates and lots of different materials systems

bull Prepare specimens in a consistent fashion to minimize variability

bull Test according to standards

bull Conduct multiple exposure sets and evaluate frequently

Perform Outdoor Testing

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 17: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

17 17M-0479 SAE INTERNATIONAL 17 17M-0479

Deliver Realistic Forces of Weathering Light

A xenon light source with proper optical filters correlates better to outdoor exposure

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 18: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

18 17M-0479 SAE INTERNATIONAL 18 17M-0479

High temperature serves primarily to accelerate water uptake Two key guiding principles

1 Do not exceed maximum service temperature

2 Use realistic temperatures to increase correlation

Deliver Realistic Forces of Weathering Heat

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 19: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

19 17M-0479 SAE INTERNATIONAL 19 17M-0479

Deliver Realistic Forces of Weathering Water

Rotating Drum Flat Array

Shielded sponge holder

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 20: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

20 17M-0479 SAE INTERNATIONAL 20 17M-0479

Develop a cycle that mimics a typical Florida outdoor daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 21: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

21 17M-0479 SAE INTERNATIONAL 21 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

10218 Not a Good Match with Outdoor Weather

Irradiance Water Spray

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 22: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

22 17M-0479 SAE INTERNATIONAL 22 17M-0479

00

01

02

03

04

05

06

07

08

09

10

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Irrad

ianc

e (W

m2 n

m

340n

m)

SAE J2527 Not a Good Match with Outdoor Weather

Irradiance Water Spray

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 23: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

23 17M-0479 SAE INTERNATIONAL 23 17M-0479

Develop a cycle that mimics a typical Florida outdoors daily cycle

0 2 4 6 8 10 12 14 16 18 20 22 24

Time (hours)

Light Intensity Panel Water Content

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 24: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

24 17M-0479 SAE INTERNATIONAL 24 17M-0479

ASTM D7869 Reproduces Natural Weather Cycles

Irradiance Water Spray

Deep Water Penetration

Adhesion Blistering Diffusion

No spray during light steps

Avoids unrealistic failures

Cyclic Stresses (cracking) Surface Erosion (gloss)

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 25: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

Chart1

Irradiance (Wm2nm 340nm)
Irradiance
Time (hours)
0
0
0
04
04
08
08
04
04
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0
0
0
0
04
04
08
08
0
0

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
0
0
4
4
45
45
9
9
95
95
12
12
125
125
125
128333333333
128333333333
148333333333
148333333333
15
15
155
155
155
158333333333
158333333333
178333333333
178333333333
18
18
185
185
185
188333333333
188333333333
208333333333
208333333333
21
21
215
215
215
218333333333
218333333333
238333333333
238333333333
24
Page 26: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

Sheet1

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Time Irradiance
0 0 0 0
0 0 0 0
4 0 00666666667 240
4 04 00666666667 240
45 04 0075 270
45 08 0075 270
9 08 015 540
9 04 015 540
95 04 01583333333 570
95 0 01583333333 570
12 0 02 720
12 0 02 720
125 0 02083333333 750
125 0 02083333333 750
125 04 02083333333 750
128333333333 04 02138888889 770
128333333333 08 02138888889 770
148333333333 08 02472222222 890
148333333333 0 02472222222 890
15 0 025 900
15 0 025 900
155 0 02583333333 930
155 0 02583333333 930
155 04 02583333333 930
158333333333 04 02638888889 950
158333333333 08 02638888889 950
178333333333 08 02972222222 1070
178333333333 0 02972222222 1070
18 0 03 1080
18 0 03 1080
185 0 03083333333 1110
185 0 03083333333 1110
185 04 03083333333 1110
188333333333 04 03138888889 1130
188333333333 08 03138888889 1130
208333333333 08 03472222222 1250
208333333333 0 03472222222 1250
21 0 035 1260
21 0 035 1260
215 0 03583333333 1290
215 0 03583333333 1290
215 04 03583333333 1290
218333333333 04 03638888889 1310
218333333333 08 03638888889 1310
238333333333 08 03972222222 1430
238333333333 0 03972222222 1430
24 0 04 1440
Page 27: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

Sheet2

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 28: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

Sheet3

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 29: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

25 17M-0479 SAE INTERNATIONAL 25 17M-0479

bull Chemical change

bull Cracking

bull Blistering

bull Adhesion loss

bull Color

bull Gloss loss

Validate Test Methods Multiple failure modes reproduced by accelerated test

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 30: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

26 17M-0479 SAE INTERNATIONAL 26 17M-0479

bull Modern accelerated lab weathering test cycles are thoroughly researched - developed using scientific understanding of outdoor weather phenomena ndash light heat and water

bull Test cycles must be validated by comparison of results to long-term outdoor weathering data of a variety of coatings systems

bull A good test standard for correlation must be realistic The example here reproduces faithfully almost all physical failure mechanisms and as a bonus is 40 faster than current test method

bull Introduction of new weathering protocols allows for more rapid and accurate accelerated weathering results These can be correlated with outdoor test data to give powerful information

Conclusions Weathering Testing

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 31: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

27 17M-0479 SAE INTERNATIONAL

Corrosion Testing

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 32: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

28 17M-0479 SAE INTERNATIONAL 28 17M-0479

Types of Accelerated Tests

Accelerated Test Type Result Test Time Results compared to

Quality Control Pass fail bull Defined bull Short

Material specification

Qualification validation Pass fail

bull Defined bull Medium-long

Reference material or specification

Correlative Rank-ordered data bull Open-ended bull Medium

Natural exposure (Benchmark site)

Predictive Service life

Acceleration factor bull Open-ended bull Long

Natural exposure (Service environment)

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 33: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

29 17M-0479 SAE INTERNATIONAL 29 17M-0479

Step 1 Continuous Salt Spray Salt Fog

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 34: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

30 17M-0479 SAE INTERNATIONAL 30 17M-0479

bull 5 NaCl salt fog at 35 degC

bull Neutral pH

bull Fine mist (atomized with compressed air) sprayed indirectly onto specimens

bull ISO 9227 contains the same test

bull When correctly followed test has reasonable repeatability and reproducibility

Continuous Salt Spray ASTM B117

100 years later ASTM B117 is still the most widely-used corrosion standard today primarily for quality control and metallicconversion coatings

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 35: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

31 17M-0479 SAE INTERNATIONAL 31 17M-0479

bull Not a good simulation of most service environments ndash not realistic

bull Typically produces different corrosion products than natural exposure

bull Poor rank order correlation with outdoor corrosion

Limitations of Salt Spray

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 36: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

32 17M-0479 SAE INTERNATIONAL 32 17M-0479

Step 2 WetDry Cyclic Tests Salt Fog Dry-Off

Exhaust Vent

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 37: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

33 17M-0479 SAE INTERNATIONAL 33 17M-0479

bull Alternating spray and dry-off

bull Development began in England 1960rsquos

bull Dilute NaCl (NH₄)₂SO₄

bull American Architectural Manufacturers Association recently replaced ASTM B117 with this test in AAMA 2605 ldquoSuperiorrdquo coatings on aluminum

WetDry Cyclic Tests Moving Forward Prohesion (Protection is Adhesion)

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 38: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

34 17M-0479 SAE INTERNATIONAL 34 17M-0479

Test Results from Early Corrosion Standards

Laboratory Test Method

Correlation wSevere Marine Environment

Conventional Salt Spray (ASTM B117) -011

Cyclic Test (Prohesion) -007

Useful passfail testshellip Worse than flipping a coin for correlation to service environment

Spearman Rank 10 = Perfect rank order 0 = Random -10 = Inverse rank order

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 39: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

35 17M-0479 SAE INTERNATIONAL 35 17M-0479

bull Poor repeatability and reproducibility

bull Poor correlation in some cases ndash Automotive ndash Industrial maintenance coatings on steel

bull Attempts to improve correlation amp repeatability includehellip ndash Wet bottom (water retained at chamber bottom) ndash Changing temperature of bubble tower ndash Both are crude ldquoworkaroundsrdquo for poor RH control technology

WetDry Cyclic Tests Limitations

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 40: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

36 17M-0479 SAE INTERNATIONAL 36 17M-0479

Step 3 Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

Wetting specimens after dry-off reinitializes corrosion

DI Water In

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 41: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

37 17M-0479 SAE INTERNATIONAL 37 17M-0479

Example GM 9540P bull NaCl and CaCl2 to simulate road salts

bull Solution applied by direct Spray not Fog

bull Salt spray applied intermittently in ldquoambientrdquo conditions

bull Use of corrosion coupons to minimize test variability

bull SAE amp American Iron amp Steel Institute rated this method best predictor of outdoor performance in 1991

First-Generation Cyclic Automotive Tests Salt Fog Dry-Off Wetting (Humid)

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 42: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

38 17M-0479 SAE INTERNATIONAL 38 17M-0479

bull Corrosion accelerates once it starts ndash Formation of complex oxides

ndash Wet time increases as new oxides form

bull Corrosion is dependent on relative humidity ndash As RH increases surface wetness increases

ndash Corrosions of metals in galvanic couples (Alsteel) strongly affected by differences in RH

Relative Humidity amp Corrosion

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 43: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

39 17M-0479 SAE INTERNATIONAL 39 17M-0479

Relative Humidity and Corrosion

Condition RH Range Result

Dry le 50 Very little corrosion from NaCl

Electrolytic cells around salt crystals film formation as RH increases

50-76 bull Corrosion of steel (maximum corroded area

~70 RH) and aluminum bull AL-Steel galvanic couple broken

Uniform Electrolytic Film formation ge76

bull Maximum cathode area for steel deeper non-uniform corrosion

bull Al corrosion in galvanic couple with steel

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 44: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

40 17M-0479 SAE INTERNATIONAL 40 17M-0479

Lack of comprehensive RH control bull Conditions limited to full wetting dry uncontrolled roomambient

bull No control of RH transition times

bull Variable specimen dry-off rates

bull No RH just below or above DRH

Slow application of salt solution (fog) bull Little time for dry-off and re-wetting of specimens

First generation cyclic automotive methods What was missing

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 45: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

41 17M-0479 SAE INTERNATIONAL 41 17M-0479

Modern Corrosion Tests Salt fogshower Dry-off Controlled RH

bull Salt ldquoFogrdquo sometimes replaced by shower

bull Controlled Relative Humidity during ldquoambientrdquo phase

bull Controlled Transition Times

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 46: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

42 17M-0479 SAE INTERNATIONAL 42 17M-0479

Modern Automotive Corrosion Tests

bull Toyota TSH1555G

bull VDA 621-415

bull Renault D17 2028

bull GMW 14872

bull Volvo VCS-1027 14 amp 149

bull Volvo VCS 423-0014

bull ISO 16701

bull Ford CETP 0000-L-467

Fog Shower

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 47: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

43 17M-0479 SAE INTERNATIONAL 43 17M-0479

Air Pre-Conditioner enables precise RH control

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 48: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

44 17M-0479 SAE INTERNATIONAL 44 17M-0479

1 Accurate control of ldquoambientrdquo conditions Either the laboratory has to be perfectly controlled or the chamber must have dehumidification

2 Accurate Ramping of Temperature amp Humidity

System starts with dry cool air and adds precise amounts of heat and humidity to achieve controlled conditions

Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 49: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

45 17M-0479 SAE INTERNATIONAL 45 17M-0479

Corrosion Test Operational Range

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 50: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

Chart1

Without Air Preconditioner
ambient RH = 60
With Air Preconditioner
dots represent set points of common automotive test methods
ambient Temp 23 degC
Temperature (degC)
RH()
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 51: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

2360 room chart

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013
600 without preconditioner600 with preconditioner
(for RH steps)
1100 without preconditioner1100 with preconditioner
ambient temperature = 23degC
ambient RH = 60
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
45
60
0
52
74
74
58
97
13
60
100
15
33
33
25
25
5
6
14
14
11
95
5
5
95
5
10
10
8
70
25
25
25
25
25
97
50
50
50
50
50
50
75
75
75
75
75
25
97
95
97
100
100
100
50
97
97
100
100
100
97
50
93
100
100
100
95
100
74
74
74
75
50
58
50
68
45
52

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
25 18 0 23 17 21 21 25
49 40 100 23 40 40 40 40
60 60 60 60 60 60
25 78 80
40 87 68 68 65
50 65 76 79 79 69
50 63 68 70 70 67
60 57 60 63 63 61
60 55
35 55 55 57 57
35
35 40 40 40 40 40
23 15 14 20 20 21
40 15 21 21 21
23 25
45 15
18 17
Page 52: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

simplified 2360 room chart

ampCampArialBoldamp18 23degC 60 RH RoomampRTest No 19359 JUL 2013
without preconditioner
ambient RH = 60
(for RH steps)
with preconditioner
ambient temperature = 23degC
dots represent set points of A rated test methods
Temperature (degC)
RH ()
Q-Fog CRH Chamber Temperature and RH Range
45
60
0
68
74
97
60
100
52
58
25
15
33
95
6
14
95
5
10
70
25
25
97
50
50
50
75
75
25
100
100
95
100
100
50
100
100
97
68
74
50
100
50
50

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
25 0 23 15 21
49 100 23 17 25
60 40 40
25 60 60
40 70 68
50 65 65
50 63 63
60 57 57
60 55 55
35 40 40
35 15 21
35 15 21
23
40
23
45
Page 53: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

2360 room data

ampCampArialBoldamp18Cool RoomampRTest No 19359 JUL 2013

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Q-Fog CRH Chamber Temperature amp Humidity Range
TEST CONDITIONS
chamber serial number 600 11-0831
1100 10-0391
chamber loading 600 (128) 4 x 12 x 0035 SS panels (8 racks - 16 panelsrack)
1100 (200) 4 x 12 x 0035 SS panels (10 racks - 20 panelsrack)
line voltage 600 233V
1100 231V
chamber voltage 230V
Set Points Actual
chamber size 600 600 1100 1100
preconditioner off on off on
chamber room chamber room chamber room chamber room chamber room chamber room chamber room chamber room
step function temp RH time temp temp RH RH temp temp RH RH temp temp RH RH temp temp RH RH
1 RH 10 5 200 25 23 58 70 18 23 45 56 24 23 74 70 17 22 52 57
2 RH 40 5 200 40 22 25 71 40 23 13 55 40 23 33 67 40 23 15 55
3 RH 60 5 200 60 24 11 68 60 23 5 53 60 25 14 65 60 23 6 53
4 RH 80 5 200 63 24 9 67 78 24 5 53 65 24 12 66 80 24 5 52
5 RH 99 5 200 65 23 8 67 77 24 5 51 68 24 10 64 87 22 5 54
6 RH 10 100 200 21 23 95 74 15 22 93 58 20 23 100 74 14 22 100 58
7 RH 40 100 200 40 23 97 70 40 23 97 59 40 24 100 68 40 23 100 58
8 RH 60 100 200 54 23 97 68 53 24 98 52 56 24 100 64 54 24 100 51
9 RH 80 100 200 55 24 97 67 55 24 97 50 57 24 100 64 55 24 100 50
10 RH 99 100 200 55 26 97 66 52 24 97 50 56 26 100 65 52 24 100 50
11 RH 10 25 200 22 25 70 62 15 24 68 56 24 24 69 62 15 21 77 66
12 RH 10 50 200 23 23 70 60 16 23 61 65 23 22 60 60 16 23 66 64
13 RH 10 75 200 21 23 75 61 15 22 74 64 21 22 74 63 15 23 74 62
14 RH 99 25 200 69 23 25 65 65 23 25 71 79 25 25 60 76 24 25 68
15 RH 99 50 200 67 24 50 62 63 22 50 63 70 24 50 62 68 24 50 58
16 RH 99 75 200 61 23 75 63 57 22 75 65 63 24 75 62 60 24 75 59
shaded cells indicate ambient damper is open
1 25 58 1 18 45 13 21 74 1 17 52
2 40 25 2 40 13 2 40 33 2 40 15
3 60 11 3 60 5 3 60 14 3 60 6
4 4 78 5 4 4 80 5
5 65 8 5 5 68 10 5 87 5
14 69 25 14 65 25 14 79 25 14 76 25
15 67 50 15 63 50 15 70 50 15 68 50
16 61 75 16 57 75 16 63 75 16 60 75
10 55 97 10 10 10
9 9 55 97 9 57 100 9 55 100
8 8 8 8
7 40 97 7 40 97 7 40 100 7 40 100
6 21 95 6 15 93 6 20 100 6 14 100
13 21 75 13 13 21 74 13 15 74
1 25 58 12
11 15 68
1 18 45 1 17 52
A rated set points
degC RH without PC with PC
25 45 21 74 15 68 23 0
49 97 25 58 17 52 23 100
60 25 40 33 40 15
25 95 60 14 60 6 0 60
40 95 68 10 70 5 100 60
50 70 65 25 65 25
50 97 63 50 63 50
60 50 57 75 57 75
60 25 55 100 55 100
35 95 40 100 40 100
35 50 21 100 15 100
35 97 21 74 15 68
23 50
40 100
23 50
45 50
Page 54: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

expert parameters

ampRTest No 193520 JUN 2013

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Q-Fog CRH Expert Parameter Settings for Determining
Temperature and Humidity Range
Q-Fog Expert Parameter Setting Q-Fog Expert Parameter Setting
X 1 DRY PROP BAND= XXXdegC 8 X 49 RH DERIVATIVE GAIN= XXX 0
X 2 DRY INTEGRAL= XXX 4 X 50 CHAMBER TEMP DERIVATIVE BAND= XXdegC 3
X 3 CHAMBER TEMP HI DEVIATION= XXdegC 10 X 51 CHAMBER TEMP DERIVATIVE GAIN= XXX 250
X 4 CHAMBER TEMP LOW DEVIATION= XXdegC 10 X 52 RH STEP TEMP PROP BAND= XXXdegC 6
X 5 CHAMBER TEMP DEV DELAY= XXX MIN 180 X 53 RH STEP TEMP INTEGRAL= XXX 6
X 7 HUMIDITY PROP BAND= XXXdegC 5 X 54 RH STEP RH PROP BAND= XXX 30
X 8 HUMIDITY INTEGRAL= XXX 12 X 55 RH STEP RH INTEGRAL= XXX 6
X 9 MINIMUM BOILER TEMP= XXdegC 60 X 56 DAMPER HYSTERESIS= XX 5
X 10 FOG PROP BAND= XXXdegC 6 X 57 SENSOR WASH DURATION= XX SEC 5
X 11 FOG INTEGRAL= XXX 6 X 58 FOG-PURGE ACTIVE yes
X 12 DWELL PROP BAND= XXXdegC 8 X 59 FOG-PURGE DURATION= XX MIN 3
X 13 DWELL INTEGRAL= XXX 4 X 60 RH STEP COOLING EFFECT COMP no
X 14 BUBBLE TOWER OFFSET= XXdegC 12 X 61 RH STEP TEMP INTEGRAL RESET no
X 15 BUBBLE TOWER PROP BAND= XXXdegC 5 X 62 SHOWER PROP BAND= XXXdegC 8
X 16 BUBBLE TOWER INTEGRAL= XXX 25 X 63 SHOWER INTEGRAL= XXX 4
X 17 BUBBLE TOWER HI DEVIATION= XXdegC 3 X 64 MAXIMUM RH CHAMBER TEMP= XXdegC 99
X 18 BUBBLE TOWER LOW DEVIATION= XXdegC 3 X 65 MAXIMUM SHOWER CHAMBER TEMP= XXdegC 99
X 21 ROUTINE SERVICE INTERVAL= XXXX HRS 999 X 66 MAX RAMP PERIOD= XXX MIN 600
X 22 RESET TOTAL TIME HOURS= XXXXX HRS 0 X 67 RH HI DEVIATION= XX 75
X 24 PREHEAT CHAMBER no X 68 RH LOW DEVIATION= XX 75
X 25 OLD SINGLE FLOAT BUBBLE TOWER no X 69 RH DEVIATON DELAY= XXX MIN 99
X 28 AMBIENT COMPENSATON FACTOR= XX 0 X 70 EVAPORATOR TEMP SETPOINT= XXdegC 7
X 29 M30M31M32 HI ERROR BAND= XXdegC 15 X 71 SPRAY RH GENERATOR ACTIVE yes
X 30 M30M31M32 LOW ERROR BAND= XXdegC 2 X 72 WET BULBDRY BULB ACTIVE yes
X 31 PURGE AIR HIGH LIMIT= XXXdegC 95 X 73 PRECOND TEMP PROP BAND= XXXdegC 19
X 32 AIR FLOW SENSOR ACTIVE yes X 74 PRECOND TEMP INTEGRAL= XXX 10
X 34 MINIMUM PUMP VOLTS= XXX 01 X 75 EVAP TEMPERATURE PROP BAND= XXXdegC 4
X 35 PURGE AIR FLOW SWITCH yes X 76 EVAP TEMPERATURE INTEGRAL= XXX 60
X 36 MAXIMUM DRY CHAMBER TEMP= XXdegC 70 X 77 CAVITY DAMPER THRESHOLD= XX 99
X 37 MAXIMUM HUMID CHAMBER TEMP= XXdegC 60 X 80 PRECOND STARTUP TIME= XXX MIN 5
X 38 MAXIMUM FOG CHAMBER TEMP= XXdegC 99 X 81 PRECOND MINIMUM OFF TIME= XXX MIN 5
X 39 MAXIMUM DWELL CHAMBER TEMP= XXdegC 60 X 82 PRECOND SETPOINT OFFSET= XXdegC 30
X 40 CHAMBER HI TEMP LIMIT= XXdegC 99 X 83 FOG STEP INITIAL COOLING TARG= XXdegC 0
X 41 COOLING EFFECT COMPENSATION no X 84 CHAMBER TEMP FILTER COEF= XX 5
X 42 DRY CYCLE INTEGRAL RESET yes X 85 CHAMBER RH FILTER COEF= XX 10
X 43 RESET ROUTINE SERVICE= XXXX HRS 0 X 86 PRECOND DAMPER MAX= XX 19
X 44 PURGE AIR FLOW ALARM DELAY= XX SEC 30 X 87 PRECOND DAMPER MIN= XX 23
X 45 PURGE AIR HEATER FAULT DEV= XXdegC 20 X 88 CHAMBER TEMP DERIVATIVE DB= XXXdegC 03
X 46 MODEL= RH X 89 RH DERIVATIVE DEADBAND= XXX 02
X 47 RH STEP RH INTEGRAL RESET no X 90 MIN SHOWER PULSE ON TIME= XXX SEC 2
X 48 RH DERIVATIVE BAND= XX 15
Page 55: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

46 17M-0479 SAE INTERNATIONAL 46 17M-0479

bull Salt spray tests are good passfail screening tests

bull WetDry tests are good comparative tests for some systems but not repeatable

bull First-generation cyclic automotive tests moved testing towards correlation but were not repeatable

bull Modern autmotive corrosion tests are more realistic and offer better repeatability and reproducibility

Conclusions Corrosion Testing

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Page 56: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

47 17M-0479 SAE INTERNATIONAL 47 17M-0479

bull Accelerated testing of both Weathering and Corrosion can be performed at different lvels of complexity yielding different sets of information (passfail qualification correlation)

bull Early weathering and corrosion tests did not accurately reproduce service environments and are typically effective only as passfail tests

bull Improved scientific research led to weathering and corrosion standards that offered some correlative power but lacked ablity to reproduce certain failures and be conducted repeatably

bull Modern weathering and corrosion standards use precise environmental control to deliver realistic reproducible testing

Conclusions Modern Accelerated Testing

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions
Page 57: WEATHERING AND CORROSION TESTING IN THE ... - … · 17m-0479 1 weathering and corrosion testing in the automotive industry: an overview of today’s requirements andy francis, q

48 17M-0479 SAE INTERNATIONAL

Questions

  • Weathering and Corrosion Testing in the Automotive Industry An Overview of Todayrsquos Requirements
  • Weathering and Corrosion
  • Weathering and Corrosion Testing
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Types of Accelerated Tests
  • Weathering Testing
  • Historical Accelerated Weathering Test Standards
  • SAE J2527 Significant improvement hellip but still a ways to go
  • Modern Weathering Test Standard Development
  • Collect outdoor weather data
  • Perform Outdoor Testing
  • Deliver Realistic Forces of Weathering Light
  • Deliver Realistic Forces of Weathering Heat
  • Deliver Realistic Forces of Weathering Water
  • Develop a cycle that mimics a typical Florida outdoor daily cycle
  • 10218Not a Good Match with Outdoor Weather
  • SAE J2527Not a Good Match with Outdoor Weather
  • Develop a cycle that mimics a typical Florida outdoors daily cycle
  • ASTM D7869Reproduces Natural Weather Cycles
  • Validate Test MethodsMultiple failure modes reproduced by accelerated test
  • ConclusionsWeathering Testing
  • Corrosion Testing
  • Types of Accelerated Tests
  • Step 1 Continuous Salt SpraySalt Fog
  • Continuous Salt SprayASTM B117
  • Limitations of Salt Spray
  • Step 2 WetDry Cyclic TestsSalt Fog Dry-Off
  • WetDry Cyclic Tests Moving ForwardProhesion (Protection is Adhesion)
  • Test Results from Early Corrosion Standards
  • WetDry Cyclic TestsLimitations
  • Step 3 Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • First-Generation Cyclic Automotive TestsSalt Fog Dry-Off Wetting (Humid)
  • Relative Humidity amp Corrosion
  • Relative Humidity and Corrosion
  • First generation cyclic automotive methodsWhat was missing
  • Modern Corrosion TestsSalt fogshower Dry-off Controlled RH
  • Modern Automotive Corrosion Tests
  • Air Pre-Conditioner enables precise RH control
  • Why the Air Pre-Conditioner is Necessary for Modern Corrosion Tests
  • Corrosion Test Operational Range
  • ConclusionsCorrosion Testing
  • ConclusionsModern Accelerated Testing
  • Questions